Solid polymer electrolytes (SPEs), comprising lithium fluorinated sulfonimide including Li[(FSO₂)(R_FSO₂)N] (R_F = n-C_mF_2m+1, m = 0 (LiFSI), 1 (LiFTFSI), 2 (LiFPFSI), and 4 (LiFNFSI)) and Li[(CF₃SO₂)₂N] (LiTFSI) as conducting salt and poly(ethylene oxide) (PEO) as polymer matrix, are utilized for investigating the impact of anionic structure of lithium salt on the performances of rechargeable lithium metal (Li) batteries (RLMBs), through comparing their fundamental physical properties, including ionic conductivity and anodic stability, and electrochemical performances for Li || Li and Li || LiFePO₄ cells. It is found that the cycling stabilities of both the Li anode and LiFePO₄ cathode are highly dependent on the structure of fluorinated imide anion. The cycling stabilities for both the Li || Li and Li || LiFePO₄ cells with Li[(FSO₂)(R_FSO₂)N] systematically outperfom those with LiTFSI at 0.2 mA cm⁻² and 80 °C (i.e., being increased in the order of LiTFSI < LiFTFSI, LiFPFSI < LiFSI < LiFNFSI for Li || Li cells, and in the order of LiTFSI < LiFSI, LiFTFSI < LiFPFSI < LiFNFSI for Li || LiFePO₄ cells). Specifically, LiFNFSI exhibits the best compatibility toward Li anode and the strongest anodic stability, thus making the Li || LiFePO₄ cell display the outstanding cycling stability (e.g., 80.8% capacity retention after 570 cycles at 1.0C and 80 °C). All the above results suggest that the structure of sulfonimide anion of lithium salt tailored for SPE-based RLMBs should have both the ability to form robust SEI films on the Li anode and strong anodic stability against the oxidation on the cathode.

固体高分子电解质（SPE），包括含Li [（FSO ₂）（R _F SO ₂）N]的氟化磺酰亚胺锂（R _F  =  n- C _m F _{2 m +1}，m  = 0（LiFSI），1（LiFTFSI ），2（LiFPFSI）和4（LiFNFSI））和Li [（CF ₃ SO ₂）₂通过比较N]（LiTFSI）作为导电盐和聚环氧乙烷（PEO）作为聚合物基质，来研究锂盐的阴离子结构对可充电锂金属（Li）电池（RLMBs）性能的影响它们的基本物理特性（包括离子电导率和阳极稳定性）以及Li ||的电化学性能 李和李|| LiFePO ₄电池。发现Li阳极和LiFePO ₄阴极两者的循环稳定性都高度依赖于氟化酰亚胺阴离子的结构。Li ||的循环稳定性 李和李|| Li [（FSO ₂）（R _F SO ₂）的LiFePO ₄电池] N]系统地优于在0.2 mA cm ^-2和80°C下具有LiTFSI的那些（即，对于Li || Li电池，以LiTFSI <LiFTFSI，LiFPFSI <LiFSI <LiFNFSI的顺序增加，并且以LiTFSI < LiFSI，LiFTFSI <LiFPFSI <LiFNFSI（对于Li || LiFePO ₄电池）。具体而言，LiFNFSI表现出与Li阳极的最佳相容性和最强的阳极稳定性，因此Li || LiFePO ₄电池显示出出色的循环稳定性（例如，在1.0C和80°C下进行570次循环后，容量保持率为80.8％）。所有以上结果表明，为基于SPE的RLMBs定制的锂盐磺酰亚胺阴离子结构应具有在Li阳极上形成坚固的SEI膜的能力以及对阴极氧化的强阳极稳定性。